Bottle inspector including a rotating photocell for scanning



June 27. 1967 H. R. ROTTMANN BOTTLE INSPECTOR INCLUDING A ROTATING PHOTOCELL FOR SCANNING Filed Dec. 1'7, 1964 HQ 1 7 'IHANS awgfim BY 27, r M

United States Patent 3,328,000 BOTTLE INSPECTOR INCLUDING A ROTATING PHOTOCELL FOR SCANNING Hans R. Rottmann, Poughkeepsie, N.Y., assignor to Owens-Illinois, Inc., a corporation of Ohio Filed Dec. 17, 1964, Ser. No. 419,047 8 Claims. (Cl. 250-223) This invention relates to inspecting glass containers and other containers having translucent walls for defects and particularly to inspecting glass containers for defects such as horizontal checks in the wall thereof.

In the manufacture of glass containers, a defect that is sometimes found which is diflicult to detect comprises a generally horizontal check or a mirror-like defect in the wall of the container. It is essential that such defects be detected even though they may be few with respect to the total number of containers being manufactured.

It is therefore an object of this invention to provide a method and apparatus for quickly inspecting hollow containers for horizontal checks in the walls thereof and rejecting those containers having such defects.

It is a further object of the invention to provide such a method and apparatus wherein the containers can be inspected while they are still hot from the forming operation.

It is a further object of the invention to provide such a method and apparatus wherein the containers can be inspected without rotation.

Basically, the invention comprises moving the hollow containers successively through an inspection station, momentarily interrupting each container at the inspection station, directing an annular ring of radiant energy to which the container is transparent downwardly and axially through the shoulder of the container to illuminate the wall and causing a portion of the light to be redirected by any checks. The invention further contemplates scanning the exterior surface of the wall by moving the line of vision of a light sensitive device, such as a photocell, to pick up such redirected portion of the light from a defect and cause it to energize the light sensitive device and produce a reject signal.

In the drawings:

FIG. 1 is a part sectional partly diagrammatic perspective view of an apparatus embodying the invention.

FIG. 2 is an enlarged, cross-sectional view of the side wall of the glass being inspected, illustrating the manner in which a check reflects the light.

Referring to the drawings, the containers C are adapted to be moved successively through an inspection station by a conveyor 10. As each container C is moved in upright position to the inspection station, it is interrupted momentarily by stopping the conveyor 10 or (as shown) by moving a stop device into the path of the container C. If the containers are hot, the stop device should preferably be heated in order to prevent thermal checking of the container.

As each container C is in position at the inspection station, an annular ring of radiant energy, such as incandescent light, to which the container material is transparent is directed downwardly through the shoulder and into the wall 11 of the container to illuminate the wall. Specifically, the light from incandescent light bulb 12 is collimated by a lens 13 and directed -downwardly through an annular aperture 14 in a mask 15. The width of the aperture 14 is substantially the same as the width of the wall 11. Light directed downwardly follows the interior of the wall in the manner of a light pipe, as is well known in fiber optics, and as represented diagrammatically by the broken arrow in the drawings.

If a defect such as a horizontal check D is present, a

3,328,000 Patented June 27, 1967 portion of the light will be redirected upwardly and outwardly through the wall 11.

A light sensitive device 16 which is sensitive to the radiant energy emitted by source 12, such as a silicon solar cell, is mounted above the container at the inspection station along with a mirror 17 and collecting lens 18. The cell16, mirror 17 and lens 18 are supported on an arm 19 which is rotatable about the axis of the container by a rotating mechanism 20 and movable axially relative to the container by a cylinder 21. Thus, the mirror 17 and lens 18 can be moved to helically scan the exterior wall 11 of the container so that the line of vision of the light sensitive device 16 scans the exterior wall. If a defect D is present, the lens 18 and mirror 17 will direct the redirected portion of the light to the light sensitive device 16. If the light sensitive device 16 is energized, the resultant signal is amplified by an amplifier 22 and caused to produce a reject signal or energize a reject mechanism 23 at the inspection station or at a subsequent point along the conveyor 10.

It can thus be seen that there has been provided a method and apparatus for inspecting the walls of hollow containers for horizontal checks quickly and efliciently and without contacting or rotating the containers so that the containers can be inspected while hot.

I claim: 1. A method of inspecting glass containers and the like for horizontal checks in the wall thereof comprising moving the containers while they are still hot from the forming opera-tion successively in upright position without rotation through an inspection station,

momentarily interrupting the movement of each container at said inspection station, directing an annular ring of radiant energy to which the article is transparent axially downwardly into the wall of the container to illuminate the wall,

causing a horizontal check in the wall of the container to reflect the portion of the radiant energy upwardly out of the Wall,

causing the line of vision of a light sensitive device to scan helically around the exterior of the wall of the container such that said reflected portion is caused to energize said light sensitive device,

and creating a signal in response to said energization.

2. The method set forth in claim 1, wherein the thickness of said annular ring of radiant energy is substantially equal to the thickness of said wall.

3. A method of inspecting glass containers and the like for horizontal checks in the wall thereof comprising directing an annular ring of radiant energy to which the article is transparent axially downwardly into the wall of the container while the container is still hot from the forming operation to illuminate the wall,

causing a horizontal check in the wall of the container to reflect the portion of the radiant energy upwardly out of the wall,

causing the line of vision of a light sensitive device to scan helically around the exterior of the Wall of the container such that said reflected portion is caused to energize said light sensitive device,

and creating a signal in response to said energization.

4. An apparatus for inspecting glass containers and the like for horizontal checks in the wall thereof which comprises.

means for moving containers successively through an inspection station,

means at said inspection station for momentarily interrupting said container at said inspection station, means at said inspection station for directing an annular ring of radiant energy to which the container is transparent axially through the Wall of the container to illuminate said wall and to cause a horizontal check to reflect and redirect a portion of the radiant energy upwardly out of said wall,

a light sensitive device,

means for mounting said light sensitive device at said inspection station in overlying relation to the container and aligned substantially with the axis of the container when the container is at the inspection station,

a mirror,

and means for mounting the mirror at a point above and radially outwardly of the wall of the container in position for reflecting a portion of the redirected portion of light from a defect to said light sensitive device,

and means for causing said mirror to rotate and move axially of the container to scan the wall of the container when the container is at the inspection station, and means for creating a signal in response tothe energization of said light sensitive device.

5. The combination set forth in claim 4, wherein said means for directing said light beam comprises a light source,

and means for mounting said light source in overlying relation to the end of the container,

and a mask interposed between said light source and said container and having an annular aperture substantially overlying the wall of the container.

6. An apparatus for inspecting glass containers and the like for horizontal checks in the wall thereof Which comprises means for directing an annular ring of radiant energy to which the container is transparent axially through the wall of the container to illuminate said wall and to cause a horizontal check to reflect and redirect a portion of the radiant energy upwardly out of said wall,

a light sensitive device,

means for mounting said light sensitive device in overlying relation to the container and aligned substantially with the axis of the container when the container is at the inspection station,

a mirror,

and means for mounting the mirror at a point above and radially outwardly of the wall of the container in position for reflecting a portion of the redirected portion of light from a defect to said light sensitive device,

and means for causing said mirror to rotate and move axially of the container to scan the wall of the container,

and means for creating a signal in response to the energization of said light sensitive device.

7. The combination set forth in claim 6, wherein said means for directing said light beam comprises a light source,

and means for mounting said light source in overlying relation to the end of the container,

and a mask interposed between said light source and said container and having an annular aperture substantially overlying the wall of the container.

8. The combination set forth in claim 4 wherein said means for moving containers successively through an inspection station comprises a conveyor,

said means at said inspection station for momentarily interrupting said container at said inspection station comprising a heated stop device movable into and out of the path of said containers.

References Cited UNITED STATES PATENTS 9/1942 Gettleman 88-14 9/1959 Miles et a1. 209111.7

OTHER REFERENCES RALPH G. NILSON, Primary Examiner.

M. ABRAMSON, Assistant Examiner. 

1. A METHOD OF INSPECTING GLASS CONTAINERS AND THE LIKE FOR HORIZONTAL CHECKS IN THE WALL THEREOF COMPRISING MOVING THE CONTAINERS WHILE THEY ARE STILL HOT FROM THE FORMING OPERATION SUCCESSIVELY IN UPRIGHT POSITION WITHOUT ROTATION THROUGH AN INSPECTION STATION, MOMENTARILY INTERRUPTING THE MOVEMENT OF EACH CONTAINER AT SAID INSPECTION STATION, DIRECTING AN ANNULAR RING OF RADIANT ENERGYH TO WHICH THE ARTICLE IS TRANSPARENT AXIALLY DOWNWARDLY INTO THE WALL OF THE CONTAINER TO ILLUMINATE THE WALL, CAUSING A HORIZONTAL CHECK IN THE WALL OF THE CONTAINER TO REFLECT THE PORTION OF THE RADIANT ENERGY UPWARDLY OUT OF THE WALL, 